Electric transformer



March 26, 1929.

J. B. HQDTUM ELECTRIC TRANSFORMER Filed March 15, 192'? avwamt oz JoMp/zBern/1am! Haitian Patented Mar. 26, 192.9e

UNITED STATES JGSEIPH BERNHARDT HOJDTUMI, U]? PITTSBURGH, PENNSYLVANIA,ASSIGNOR TO EITTSBURGH QPEANQFQRMER COMPANY, A CORPORATION OFPENNSYLVANIA.

ELECTRIC TRANSFORMER.

Application filed March 15, 1927. Serial No. 175,457.

This invention relates to electric transformers which are adapted to beimmersed in oil contained in a tank or casing and more particularly tomeans for circulating the oil t; through the tank.

I have found that is important to maintain a high rate oi circulation ofthe oil with in a transformer tank for the purpose of more rapidlycooling the oil which is heated In by the working oil" the transformercontained in the tank. This increases the rate of radiation of the heatand maintains lower tempera ture at the transforinein The object of thepresent invention is to provide at system for maintaining and increasingthe rate of circulation within the transformer tank to eliiectively andrspidly cool the oil heated by the operation of the transformer immersedin the oil within the tank.

further object of the invention is to coin hine the system with thetransformer circuits in such a way that the rapidity of the circulartionwill vary with the load increasing; with an increasing load anddecreasing with e. decreasing load.

Further objects and advantages will he spparent from the followingspecifications the accompanying drawings in which igure 1 is a sideelevation of a transformer tank with portions broken away to morecleerly illustrate the invention, and

Figure 2 is a sectional vicw'tshen on line 2-2 of Figure 1.

Figure 3 is an enlarged sectional view on line 3-8 of Figure 1, and

Figure 4: is a diagraniniaticsl View the hlowcrnniotor connection to thetransformer.

in the drawings a tonic adapted to con tain oil and the electriczuiparatus inuuerseci therein is provided with a series ot rudia'lors llcommunicating with the interior of the tank The radiators ll communicatewith 'terior of the tank 10 by means of oil or connections 12 act thetop and oil psssuges or connections 13 at the bolt the tank. ihe oilwithin the tenh'. on .hested hy the operation of the electric rntustherein will expand and to of the tank, pass out through cor radiators11 Where it is cooler; turned to the tank through the co 18 at thebottom, thus completing of circulation for coolin the oil To increasethis rate ot nstursl circuletion of the oil a portion of the oil iswithdrawn fronrthe tank through pipe connection 14 entering the interiorof the tank at the bottom and which extends above the bottom of the tankand terminates adjacent the top of the tank. The pipe connection can beso sitnoted that the oil may be withdrawn from any part of the tank andthe position of the pipe connection 14 as shown in the drawings isnierely one illustrative position of the same. 'l ne pipe connection 14is attached to the suction or inlet of an oil pump 15 which is operetedby an electric motor 16. The motor 16 is connected to the secondarywinding 17 of the transformer contained. within the tank l6. The primarywinding 18 of the trans- :tornier is in series with the load so that thespeed of the motor 16 will var with the load. it will he readily seenthat the speed the motor 16 which drives the circulating oil 15 willmrywith the load on the tra :lSfOl'InGi and the circulation of the oilvaried accordingly. The oil is forced under pressure hy the oil pumpthrough a pipe connection 19 connected to the outlet of the pump. Thepipe connection 19 merges into and is connected to an annular header 20encircling the bottom of the tank adjacent to and above the radiatorconnections 13. The oil is therefore forced through the annular header20 circulating about the tank. This annular header is provided withdownvmrdl'v ext-ending inject tubes :21 st each rsdisto r connectionwhich enter the connections through a fluid tight joint and are providedwith inwardly directed tips or nozzles 22 located at the centre of theconnection 13 where the connections are attached to the trans formercasing.

It is up arent that the oil on heinp; forced through t is injector tuhes21 under pressure and at a greater velocity than the oil passing throughthe connections l3 hy normal circulation will impart energ rounding thetips 22 causing" the velocity of oil nections 13., consequentlycausingan in creased rate of circulation throughout the entire circul 1gsystem, thus providing an increased rote of cooling of the oil and a.more eiitlcient operation of the electric apparatus cont ned within thetank.

.111 the cii-i. ulntory system of this invention 2. single plifllp isused to drew increased cir culetion through each 0" eithan inert-vase into the oil sur :(lll

passing through the conout in any Way impairing or interfering with thenatural gravity circulation. \Vhere the pump drive is connected tovaryin speed with the load the circulation is also automaticallycontrolled to have a maximum effect when the greatest cooling isrequired, at the same time saving in current and avoiding excessivecooling at low loads and stopping thepower circulation automaticallywhen the transformer loadis substantially cut oil'. ,In case offailure/of the pump or with Very low loadsor no load the natural gravitycirculation through the cooling tankswill come into full eilectmaintaining a cooling circulation snflicient to avoid dangerous rise ain the temperature transformer.

I claim:

1. A transformer tank adapted to contain oil, a transformer in saidtank, radiators for said tank having top and bottom connections to theinterior of said tank, injector tubes connected to the interior of thebottom connections of said radiators for increasing the circulation ofthe oil within the tank.

52. A transformer tank adapted to contain oil, a transformer in saidtank, radiators for said tank having top and bottom connections to theinterior of said tank, injector tubes connected to the interior of thebottom connections of said radiators for'increasing the circulation ofthe oil within the tank and means for forcing the oil through saidinjector tubes in' proportion to the load on the transformer.

3. A.transi'or1ncr tank adapted to contain oil, a transformer in saidtank, radiators for said tank having'top and bottom connections to theinterior of said tank, injector tubes connected to the interior of thebottom connections of said radiators for increasing the circulation ofthe oil Within the tank and an oil pump for forcing oil through saidinjectors.

4. A transformer tank adapted to contain oil, a transformer in saidtank, radiators for said tank having top and bottom connections to theinterior of said tank, injector tubes connectcd to the interior of thebottom connections of said radiators for increasing the circulation ofthe oil within the tank and an oil pump for forcing the oil through saidintransformer. i r I 5. A transformer tank adapted to contain oil, atransformer in said tank, radiators for said tank having top and bottomconnections to the interior of said tank, injector tubes connected tothe interior of the bottom connections of said radiators for increasingthe circulation of the oil within the tank and means operated by saidtransformer for forcing the oil through said injector tubes inproportion to the load on the transformer.

1 6. A transformer tank adapted to contain oil, a transformer in saidtank, radiators for said tank having top and bottom connectionsinjector.

7. A transformer tank adapted to contain oil, a transformer in saidtank, radiators for said tank having top and bottom connections to theinterior of said tank, an annular header, injector tubes protruding fromsaid header and extending into the radiator connections adjacent to thebottom of the tank and an oil pump for forcing oil from said tankthrough said header and injector tubes to in crease the rate ofcirculation of the oil through the interior of the tank.

8. A transformer tank adapted to contain oil, a transformer in saidtank, a radiator for said tank having top and bottom connections to theinterior of said tank said radiator and tank constituting an oilcircuit, means for increasing the flow in said circuit comprising aconduit extending from a point at one level of the oil in said tank toanother level, said conduit terminating at said other level in one ofsaid connections and having its dischar e opening directed in the normaldirection of flow in said circuit, and a pump interposed in saidconduit. i

9. A transformer tank adapted to contain I oil, a transformer in saidtank, a radiator for said to nk having top and bottom connections to theinterior of said tank, said radiator and tank constituting an oilcircuit, and an injector tube disposed in one of said connec tions, saidtube being directed in the normal direction of How in said circuit forincreasing said How.

10. A transformer tank adapted to contain oil, a transformer in saidtank, a radiator for said tank having top and bottom connections 1 I r jto the interior of said tank, said radiator and Jector tubes inproportion to the load on the tank constituting an oil circuit, aninjector tube disposed in one of said connections, said tube. beingdirected in the normal direction of How in said circuit for increasingsaid flow, and an oil pump connected to said tank for re moving oiltherefrom and forcing it through said injector.

JOSEPH BERNHARDT HODTUM.

